Process of producing white lead.



EDWIN nusron,

OF ST. LOUIS,

MISSOURI.

PROCESS OF PRODUCING WHITE LEAD.

No Drawing.

To all whom it may concern 7 Be it known that I, EDWIN EUsToN, a. citizen of the United States, residing at city of St. Louis, State of Missouri, have invented a certain new and useful Improvement in Pirocesses of Producing White Lead, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to a process of producing white lead, my object being to provide a new and easily practised method whereby white lead of the best quality can be easily, cheaply and rapidly produced.

I have discovered that by separately preparing and subsequently mixing together the relatively bulky precipitate formed by carbon dioxid gas acting onbasic lead acetate solution until said solution is eventually approximately neutral chemically, and the relatively dense precipitate obtained by carbon dioxid gas acting on basic lead acetate solution until of acid reaction, a pigment is obtained which has opacity, white ness, spreading and brushing qualities in every way equal to the best known commer cial grades of white lead.

One simple and practical way of practising my improved process consists in preparing, in any of the known ways, a solution of basic lead acetate of preferably 20 degrees Baum (neutral point about 10 degrees Baum) and spraying said solution through an atmosphere of either dilute or strong carbon dioxid gas in a suitable vessel by a circulating pump until the solution is approximately neutral, 2'. 0., neither distinctly alkaline nor acid. A second and similar solution of basic lead acetate is then prepared and dioxid gas until of-acid reaction. The two above described steps may be practised in separate apparatus or alternately in one apparatus and the two products may be directly mixed upon discharge from said apparatus and the so-mixed precipitates removed together from the solution by settling or other known means in preparation for the market;

Specification of Letters Patent.

similarly treated with carbon.

Patented Aug. 11, il ilel.

Application filed September 10, 1913. Serial No. 789,0S9.

or the two products may be separately settled and the two precipitates so freed from the solutions may then be mixed either be fore or after drying or before or after mixing with linseed oil in preparation for the market. The strength of solution, the strength of carbon dioxid gas, the pressure of carbon dioxid gas, the temperature and the form of apparatus may be varied and are not essential to the basic idea of my invention which consists in, first, the precipitation of a pigment by carbon dioxid gas from basic lead acetate solution eventually approximately neutral chemically, second, the precipitation of a pigment by carbon dioxid gas from basic lead acetate solution eventually acid, and third, the mixing of said two pigments together in proportions to produce a pigment containing approximately from 11.0% to 14:.570 carbon dioxid as desired.

I claim as my invention:

1. The process of manufacturing white lead consisting, first, in forming a precipitate by carbon dioxid gas from basic lead acetate solution eventually approximately neutral chemically, second, in forming a precipitate by carbon dioxid gas from basic lead acetate solution eventually acid, and third, in mixing the two products thus obtained in proportions to form a pigment containing 11.0% to 1 1.5% carbon dioxid.

2. The process of producing white lead consisting in the admixture of a precipitate formed by carbon dioxid gas from a basic lead acetate solution eventually approximately neutral, with precipitate formed by carbon dioxid gas from basic lead acetate solution eventually acid, in proportions to form a pigment containing 11.0% to 14.5% carbon dioxid.

In testimony whereof I hereunto aflix my signature in the presence of two witnesses, this 4th day of September, 1918.

EDWIN EUSTON.

Witnesses:

M. P. SMITH, M. A. I-IANDEL.

copies at this patent may be obtained for five cents each, by addressing the Commissioner or IEatents, Washington, D. 0. 

